1. Field of the Invention
The present invention relates to a computer expansion device with a universal serial bus (USB) interface, more particularly to an expansion device having computer peripheral devices coupled to a USB interface signal Input/Output to meet the expansion requirements of portable computer.
2. Description of the Related Art
The development of computer tends to be compact in its design; the notebook computer among the portable computers is a good example. Since the integrity of computer functions is taken into consideration, therefore the optical disk drive, hard disk drive, floppy disk drive, and battery are indispensable peripheral devices. As to the actual computer operation, users generally install the operating system and application programs in a hard disk drive for their actual applications, and the notebook computer is usually used in the office or at home. Therefore, some computer manufacturers broke through the long existing hardware architecture of the notebook computer and developed a so-called “Desknote” computer. Such desknote computer removes some of the peripheral devices from the computer and definitely greatly reduces the weight and thickness of the computer. Therefore, the future computer system architecture only includes a motherboard, a hard disk drive and a housing, and the rest of peripheral devices will be connected to a computer externally.
If the aforementioned peripheral devices are connected to a computer with different ways and since the motherboard cannot provide so many ports, therefore repeatedly plugging and unplugging the devices will trouble the users very much. No doubt, notebook computers may use a docking station to connect different peripheral devices, but the pin assignment of the connector is custom-made with a specific specification depending on the port available on the notebook computer, which usually cannot fit all of the requirements and that is what users have been complaining the most. Therefore, using a common computer interface for sufficiently connecting the peripheral devices is an issue that manufacturers have to overcome.